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There’s something so refreshing every September when the temperature begins to drop, and the light gradually darkens in the evening. It makes us want to sit down with a cup of coffee and start anew on various projects: whether they’re for school, work, or our own independent creative endeavors.

Now, there’s research to back up the notion that the fall is a time for increased productivity (and perhaps explains why schools choose to be out during the summer). Economists from the University of Illinois and the University of California, Berkeley have found that hot temperatures actually decrease your work efficacy, especially if the temperatures are above 59 degrees Fahrenheit. They found that people work less and thus earn less money; and not only is this relevant for individuals, but it impacts the economy too, making it fare worse during hot days.

The study, released by the National Bureau of Economic Research, found that days with a temperature of around 77 degrees actually decreased people’s income by about $5 per day. In addition, average economic productivity fell by about 1 percent for every degree Fahrenheit above 59 degrees. And the paper warns that if climate change continues, it could have a negative impact on the economy.

So what’s the most productive temperature range? It’s somewhere between 54 and 59 degrees, according to Solomon Hsiang of Berkeley, a co-author of the study. That’s the sweet spot, where apparently you’ll get the most work done.

Previous research found a strong link between hotter climates and increased violence. “Researchers in social psychology have studied the relationship between temperature and aggression for many decades,” Richard Larrick, a professor at Duke’s Fuqua School of Business, and an author of a study about hot temperatures and increased aggression, told the Washington Post in an e-mail. “Research in the laboratory allowed for tightly controlled tests to show that changes in temperature directly lead to more aggression.” He notes that “heat changes the way people feel and think, increasing anger and making thoughts of aggression increase.” Another study published in 2013 found that higher temperatures were linked to increased conflict around the world, including crime and domestic violence.

A 2009 study, meanwhile, examined a similar relationship between climate and productivity, finding that “increased occupational heat exposure due to climate change may significantly impact on labor productivity and costs unless preventive measures are implemented,” the authors wrote. “Workers may need to work longer hours, or more workers may be required, to achieve the same output and there will be economic costs of lost production and/or occupational health interventions against heat exposures.”

But the current study has not yet been peer-reviewed, so take it with a grain of salt: some economists claim it’s rubbish, while others believe it’s ground-breaking. The ones in awe of the study are mostly climate change activists, such as Chris Field, a Carnegie Institute scientist and head of a UN climate change science panel. “It may take some time for the community to reflect on the methods to decide if they are as effective as they seem, but my first impression is that this study provides unique insights into the big-picture consequences of temperature variation for income,” Field said, according to CBS Boston.

And scientists still aren’t quite sure why this link exists – it might have something to do with our tendency to get distracted more easily when it’s sunny and beautiful outside (and wish we were outside enjoying it), whereas on rainy days and cold days we’re more likely to focus on work.